Spinnerette nozzles



Sept. 26, 1961 l. Rossl 3,001,230

SPINNERETTE N OZZLES Filed Jan. 29, 1959 2 Sheets-Sheet 1 VENTOR. 1/0 Ia IRVI ROSSI AT TO RNEYS Sept. 26, 1961 1. R088! 3,001,230

SPINNERETTE NOZZLES Filed Jan. 29, 1959 2 Sheets-Sheet 2 INVENTOR. IRVING ROSSI AT TORNEYS United States Patent 3,001,230 SPINNERE'ITE NOZZLES Irving Rossi, Morristown, N .J assignor to Eltherma A.G., Vaduz,Liechtenstein, a corporation of Liechtenstein Filed Jan. 29, 1959, Ser. No. 789,821 Claims- (C1. 18-8) I the flow in the spinnerette nozzle are caused which turbulence interferes with the spinning operation.

With a discharge orifice ofcircular cross-section, a gradual change of nozzle diameter from the intake to the spinningv orifice has been used to improve material flow. An example of such construction is shown in US. Patent No. 2,341,555.

However, gradual decrease to the discharge orifice does .not completely solve the problems involved at higher flow rates, since it fails to destroy the circular and longitudinal turbulence involved. Further, at the higher extrusion speeds, the greater velocity of the material along the conical sides tends to pinch off the very fine filament being extruded.

Further, it has been found desirable to employ spina nerettes having shaped discharge orifices (such as stars and crosses) instead of a circular cross-section. With such shaped discharge orifices the problem of material flow during extrusion becomes increasingly acute. For

example, in a cross shape spin hole, difliculty with filling;

the ends of the cross members has been experienced.

It is, therefore, one object of my invention to provide an improved spinnerette nozzle for the extrusion of viscous material without the creation of interfering turbulent disturbances. a

It is a further object of my invention to provide an improved spinnerette nozzle for extruding filaments having geometrically shaped cross-sections.

Other objects and advantages will be described in the specification, pointed out in the claims, and illustrated in the accompanying drawings of which:

FIGURE 1 is an axial cross-sectional view of a nozzle in a counterbored spinnerette.

FIGURE 2 is a top plan view of the nozzle shown in FIGURE 1.

FIGURE 3 is an axial cross-section of another embodiment of the spinnerette nozzle embodying this invention.

FIGURE 4 is an axial cross-section of another embodiment of this invention.

FIGURE 5 is a top plan view of the nozzle shown in FIGURE 4.

FIGURE 6 is a top plan view of another embodiment of this invention.

FIGURE 7 is a plan view of another embodiment of this invention for use with a spinnerette nozzle having a cross shaped orifice.

FIGURE 8 is an axial cross-section taken through lines 88 of FIGURE 8, and

FIGURE 9 is an axial cross-section taken through lines 9-9 of FIGURE 8.

In FIGURE 1, there is shown a spinnerette 10 in which there is a counterbore 11. The plate 12 at the bottom of the counterbore is sufficiently strong to withstand the material pressure required to extrude the plastic material 3,001,230 Patented Sept. 26, 1961 ice through the nozzle 14 which extends through the plate 12 from the pressure side 16 to the discharge side 18 thereof.

The spinnerette 10 is dimensioned to withstand the extruding pressures. Since it would be difiicult to drill the tiny spinnerette nozzle through this heavy plate, smaller areas are counterbored to leave a thinner nozzle plate which is sufiiciently strong to withstand the smaller total force imposed by the extruding pressure. At lower pressures or with less viscous materials, the entire spinnerette plate may be thin and the nozzle drilled therethrough. Since this invention is directed at the nozzle arrangements, the following description and illustration will be directed thereto, it being understood that the nozzle may extend through the bottom plate of a counterbore in a spinnerette or through the spinnerette itself.

The nozzle comprises a cylindrical discharge orifice 20 extending from the discharge surface of the plate. An annular wall 22, integral with the discharge orifice wall, extends upwardly therefrom to the pressure surface 16 of the plate. The annular wall is flared outwardly in a cone to provide means for graduating the velocity of extruded material as it passes from the extruder to the discharge opening. As described thus far, the construction is similar to that shown in US. Patent No. 2,341,555.

In order to alleviate any rotational turbulence in the flow and to alleviate longitudinal turbulence occurring near the edge 24 between the Wall of the discharge orifice and the conical wall 22, a plurality of guide channels 26 are provided. The guide channels are formed in the conical wall to provide means for feeding material into the discharge orifice below edge 24. It has been found preferable to form the channels with an outward taper and to round the channel into a curve 28 as it enters the discharge orifice.

The channels extend radially from the discharge orifice as is best understood by reference to FIGURE 2.

Because of the small dimensions of such nozzles, it has been found that the nozzle is best formed by electron beam machining; that is, by directing a controlled beam from an electron gun to machine the material into the desired shapes. The plate material must be sufficiently strong to resist distortion by the extrusion pressure. For this purpose, for example, stainless steel is satisfactory.

In FIGURE 3 there is shown a plate 12 having a pressure face 16 and discharge face 18.

A spinnerette nozzle extends through the plate and has a cylindrical discharge orifice 30. Extending from the top of the discharge orifice to the pressure face is an annular wall 32 integral with the wall of the discharge orifice. The wall flares outwardly in hyperbolic curve. Guide channels 34 are machined in the annular wall 32 to extend outwardly in a hyperbolic curve. The guide channels extend radially outwardly as with the embodiment shown in FIGURE 2. The channels operate as explained in connection with the embodiment shown in FIGURES l and 2. However, the transition from channel to orifice is a smoother curve.

It is often found desirable to provide a plurality of guide channels for flow control. An example of such an embodiment is shown in FIGURE 4. There is shown the plate 12 with a nozzle extending therethrough from the pressure face 16 to the discharge face 18. The nozzle comprises a cylindrical discharge orifice 40. Extending from the top of the discharge orifice to the pressure face are a plurality of guide channels 42. The guide channels are cut into the plate material flaring outwardly from the annular surface of the discharge orifice and widening to be contiguous one to the other as is best shown in FIGURE 5. Thus the guide channels terminate in semi-circular discharge openings 44 in the discharge discharge orifice tangentially. give improvedflow control under some circumstances.

1 from a circular dischargeiorifice. In; spinning -material composed of long molecular chains, such as the, various polymerizedplastics, the nozzleshown in FIGURE-'6 may. advantageously be employed.

..III 'FI GURE 6 there is shown a discharge orifice 60 from the top ofwhich guide channels 62 extend to the pressure face of the plate.

The guide channels extend outwardly in a spiral form so that-material enters the This has been found to In those applications where it is desired that the spun .1 filament have a cross-sectional shape other than that of a circle, the arrangement shown in FIGURES 7, 8 and 9 may advantageously be employed.

In the figures, there is shown a discharge orifice 80 inthe shape of a cross. 1 Extending from the ends of the I cross are guide channels 82 extending upwardly to the pressure face '16. Guide channels 84 and 86 extend from i the cross arms to thepressure face 16 of plate 12. The 'guide..channe1s84,;86, enter the cross arms at different positions 88 and 90 respectively on each side of the cross arms but for convenience of construction are joined into a single feed channel 592 near the pressure face. By this arrangement means for feeding the discharge orifice at various points to insure uniformity of flow rate and continuous filling ofxthe discharge orifice is provided.

By such means, the tendency of the plastic material leaving the discharge orifice .to form itself into a cylindrical filament is eliminated. With discharge orifices of such shapes it has beenfound that the different parts of the orifice willoffer, different resistance to the flow of extrusion material, thus creating turbulence.

The guide channels, supplying material to high resistance portions,

" eliminate turbulence and insure that the rate of material flow during extrusion is held constant for all parts of the discharge orifice.

1. A spinnerette nozzle extending through a plate from ,the pressure face to the discharge face thereof, comprising a discharge orifice extending inwardly from the discharge face to a plane between the discharge and pressure faces of the plate, a wall portion integral with the discharge orifice at said plane and flaring outwardly therefrom to the pressure face of said plate, and a plurality of guide channels formed in said outwardlyflared wall portion, said channels extending from said pressure face and terminating in said discharge orifice below. said plane.

2. A spinnerette nozzle in accordance with claim 1 in which said guide channels extend radially outwardly.

-3. A spinnerette nozzle in accordance with claim 1 in which said channels are flared outwardly from said, discharge orifice in a hyperbolic curve. i

4. A spinnerette nozzle according to claim l ingwhich said guide channels extend outwardlyin a-spir'al.

5. A spinnerette nozzle according to claim 1 in which said discharge orifice is in the form of a cross and said guide channels extend betweenjthe ends of the arms of the cross and thepressure .face of .said plate.

6. A spinnerette nozzle according to claim 1 inwhich said discharge orifice is the shape of a cross and in which said guide channels extend fromthe rnidpoints of the arms of the cross to said pressure face.

7. A spinnerette nozzle according to claim 1 in which said dischargeorifice isof circular cross section and in which said wall portion is a surface of revolution.

8. A spinnerette nozzle according to claim 1 in which said channels are contiguous.

9. A spinnerette nozzle in accordance with claim 1 in which saidorifice has a cross-sectional shape which is not radially symmetrical, and said channelsextend in fluid transfer relationship from the wall of said orifice at positions of high flow resistance to the pressure face'of said plate.

10. Aspinnerette nozzle according to claim 1 in which the discharge orifice offers diflferent resistance to-fiuid flow therethrough at different parts thereof and said guide channels are positioned ,to' maintain a constant rateiof' flow through said. discharge orifice.

References, Cited in thefile of this patent UNITED. STATES PATENTS Great Britain Mar. 24,1954 

